using System;
using System.IO;
using System.Runtime.CompilerServices;

namespace Tamir.Streams
{
	/*
	 * @(#)PipedOutputStream.java	1.26 03/12/19
	 *
	 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
	 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
	 */

	/**
	 * A piped output stream can be connected to a piped input stream 
	 * to create a communications pipe. The piped output stream is the 
	 * sending end of the pipe. Typically, data is written to a 
	 * <code>PipedOutputStream</code> object by one thread and data is 
	 * read from the connected <code>PipedInputStream</code> by some 
	 * other thread. Attempting to use both objects from a single thread 
	 * is not recommended as it may deadlock the thread.
	 *
	 * @author  James Gosling
	 * @version 1.26, 12/19/03
	 * @see     java.io.PipedInputStream
	 * @since   JDK1.0
	 */
	public class PipedOutputStream : Tamir.SharpSsh.java.io.OutputStream
	{

		/* REMIND: identification of the read and write sides needs to be
			more sophisticated.  Either using thread groups (but what about
			pipes within a thread?) or using finalization (but it may be a
			long time until the next GC). */
		private PipedInputStream sink;

		/**
		* Creates a piped output stream connected to the specified piped 
		* input stream. Data bytes written to this stream will then be 
		* available as input from <code>snk</code>.
		*
		* @param      snk   The piped input stream to connect to.
		* @exception  IOException  if an I/O error occurs.
		*/
		public PipedOutputStream(PipedInputStream snk)
		{
			connect(snk);
		}
    
		/**
		* Creates a piped output stream that is not yet connected to a 
		* piped input stream. It must be connected to a piped input stream, 
		* either by the receiver or the sender, before being used. 
		*
		* @see     java.io.PipedInputStream#connect(java.io.PipedOutputStream)
		* @see     java.io.PipedOutputStream#connect(java.io.PipedInputStream)
		*/
		public PipedOutputStream() 
		{
		}
    
		/**
		 * Connects this piped output stream to a receiver. If this object
		 * is already connected to some other piped input stream, an 
		 * <code>IOException</code> is thrown.
		 * <p>
		 * If <code>snk</code> is an unconnected piped input stream and 
		 * <code>src</code> is an unconnected piped output stream, they may 
		 * be connected by either the call:
		 * <blockquote><pre>
		 * src.connect(snk)</pre></blockquote>
		 * or the call:
		 * <blockquote><pre>
		 * snk.connect(src)</pre></blockquote>
		 * The two calls have the same effect.
		 *
		 * @param      snk   the piped input stream to connect to.
		 * @exception  IOException  if an I/O error occurs.
		 */
		[MethodImpl(MethodImplOptions.Synchronized)]
		public virtual void connect(PipedInputStream snk)
		{
			if (snk == null) 
			{
				throw new NullReferenceException();
			} 
			else if (sink != null || snk.connected) 
			{
				throw new IOException("Already connected");
			}
			sink = snk;
			snk.m_in = -1;
			snk.m_out = 0;
			snk.connected = true;
			//int t=0;
		}

		/**
		 * Writes the specified <code>byte</code> to the piped output stream. 
		 * If a thread was reading data bytes from the connected piped input 
		 * stream, but the thread is no longer alive, then an 
		 * <code>IOException</code> is thrown.
		 * <p>
		 * Implements the <code>write</code> method of <code>OutputStream</code>.
		 *
		 * @param      b   the <code>byte</code> to be written.
		 * @exception  IOException  if an I/O error occurs.
		 */
		public virtual void write(int b)
		{
			if (sink == null) 
			{
				throw new IOException("Pipe not connected");
			}
			sink.receive(b);
		}

		/**
		 * Writes <code>len</code> bytes from the specified byte array 
		 * starting at offset <code>off</code> to this piped output stream. 
		 * If a thread was reading data bytes from the connected piped input 
		 * stream, but the thread is no longer alive, then an 
		 * <code>IOException</code> is thrown.
		 *
		 * @param      b     the data.
		 * @param      off   the start offset in the data.
		 * @param      len   the number of bytes to write.
		 * @exception  IOException  if an I/O error occurs.
		 */
		public override void write(byte[] b, int off, int len)
		{
			if (sink == null) 
			{
				throw new IOException("Pipe not connected");
			} 
			else if (b == null) 
			{
				throw new NullReferenceException();
			} 
			else if ((off < 0) || (off > b.Length) || (len < 0) ||
				((off + len) > b.Length) || ((off + len) < 0)) 
			{
				throw new IndexOutOfRangeException();
			} 
			else if (len == 0) 
			{
				return;
			} 
			sink.receive(b, off, len);
		}

		public virtual void write(byte[] b)
		{
			write(b, 0, b.Length);
		}

		/**
		 * Flushes this output stream and forces any buffered output bytes 
		 * to be written out. 
		 * This will notify any readers that bytes are waiting in the pipe.
		 *
		 * @exception IOException if an I/O error occurs.
		 */
		[MethodImpl(MethodImplOptions.Synchronized)]
		public override void flush()
		{
			if (sink != null) 
			{
				lock (sink) 
				{
					//sink.notifyAll();
					System.Threading.Monitor.PulseAll(sink);
				}
			}
		}

		/**
		 * Closes this piped output stream and releases any system resources 
		 * associated with this stream. This stream may no longer be used for 
		 * writing bytes.
		 *
		 * @exception  IOException  if an I/O error occurs.
		 */
		public override void close() 
		{
			if (sink != null) 
			{
				sink.receivedLast();
			}
		}

		///////////////////////////////////////
		

		public override int Read(byte[] buffer, int offset, int count)
		{
			return 0;
		}

		public override int ReadByte()
		{
			return 0;
		}
		
		public override void WriteByte(byte value)
		{
			this.write(value);
		}

		public override void Write(byte[] buffer, int offset, int count)
		{
			this.write(buffer, offset, count);
		}
		public virtual void Write(byte[] buffer)
		{
			this.Write(buffer, 0, buffer.Length);
		}
		public override void Close()
		{
			base.Close ();
			this.close();
		}
		public override bool CanRead
		{
			get
			{
				return false;
			}
		}
		public override bool CanWrite
		{
			get
			{
				return true;
			}
		}
		public override bool CanSeek
		{
			get
			{
				return false;
			}
		}
		public override void Flush()
		{
			this.flush();
		}
		public override long Length
		{
			get
			{
				return sink.Length;
			}
		}
		public override long Position
		{
			get
			{
				return sink.m_in;
			}
			set
			{
				throw new IOException("Setting the position of this stream is not supported");
			}
		}
		public override void SetLength(long value)
		{
			throw new IOException("Setting the length of this stream is not supported");
		}
		public override long Seek(long offset, SeekOrigin origin)
		{
			return 0;
		}
	}

}
